# 钟奕升
while 1:
    sr = input("输入一个字符串")
    left = 0
    right = len(sr) - 1
    while left < right:
        if sr[left] != sr[right]:
            print("字符串不对称", sr)
            break
        else:
            print("字符串对称", sr)
            break
        left += 1
        right -= 1
